1. Field of the Invention
The present invention relates generally to armrests for seats. More particularly, the invention concerns a vertically adjustable armrest for use in connection with furniture and with passenger vehicles such as aircraft, trains and busses.
2. Discussion of the Prior Art
Various types of seat armrests for use in passenger vehicles have been suggested in the past. As a general rule, these armrests are fixedly mounted to either the seat or back portion of the seat. In those instances where the armrests are adjustable, the armrest is typically pivotally mounted to the seat back in a manner to enable the armrest to be pivoted along an arcuate path from a downward operational position into a retracted, stowed position.
On occasion, attempts have been made to develop self-leveling chair arms for use in theaters and the like. An example of one such attempt is disclosed in U.S. Pat. No. 4,400,033 issued to Pietsch. This patent concerns a theatre, or stadium chair having a seat, a seat back and an arm connected to the seat back by means of a parallelogram linkage. With this arrangement, when the seat back pivots the arm stays essentially parallel to the seat.
As a general rule, prior art self-leveling armrests as well as other prior art adjustable armrests of similar complexity have been proven to be impractical for use in vehicles. For the most part, such prior art adjustable armrests are difficult to manufacture, are of relatively high cost and are of questionable reliability. Accordingly, there has been a long felt need for an easy-to-use adjustable armrest that is of a simple construction, one that can be manufactured for reasonable cost and one that can be safely used in vehicle applications, including commercial aircraft applications. The thrust of the present invention is to provide such an adjustable armrest.